The goal of this proposal is to secure funding to add microSPECT capability to the Center for Molecular and Genomic Imaging, a core facility at UC Davis that provides the infrastructure and expertise to conduct in vivo imaging studies in animal models. We propose to incorporate a commercial microSPECT system (Siemens +SPECT) within our existing microCT scanner (microCATII, Siemens) to provide both standalone SPECT and SPECT/CT capability. The microSPECT system is based on two gamma camera heads employing pixelated NaI (Tl) detectors. The system comes with a range of pinhole, multi-pinhole and parallel hole collimators to suit different energy gamma-ray emitters and different imaging requirements. For an object 1 cm from the 0.5 mm single pinhole collimator, the reconstructed spatial resolution is 0.6 mm and the sensitivity is 80 cps/MBq. The system will be placed in our core facility and used to support NIH-funded research ranging from cancer to orthopedics to cellular therapies, and will also be used to evaluate the pharmacokinetics of a range of new diagnostic and therapeutic agents under development by UC Davis faculty. Relevance: The field of molecular imaging seeks to discover new approaches to imaging specific biologic targets and pathways in vivo, with the ultimate goal of providing patient-specific and molecularly-based diagnostic information. In addition molecular imaging approaches are being developed to directly monitor molecularly- targeted therapies, cellular therapies and gene therapies. SPECT/CT is a translational technology that combines molecular imaging (SPECT) and structural imaging (CT) and provides a platform for developing new molecular imaging technologies in the preclinical environment for ultimate translation into patient care. [unreadable] [unreadable] [unreadable]